Merge pull request #1595 from PanYuHaa/master

更新0129.求根到叶子结点数字之和中，增加0100.相同的树go语言的递归解法，增加0005.最长回文子串增加go语言的dp解法

problems/0005.最长回文子串.md

@@ -363,6 +363,34 @@ class Solution:
 Go：
 
 ```go
+func longestPalindrome(s string) string {
+    maxLen := 0
+    left := 0
+    length := 0
+    dp := make([][]bool, len(s))
+    for i := 0; i < len(s); i++ {
+        dp[i] = make([]bool,len(s))
+    }
+    for i := len(s)-1; i >= 0; i-- {
+        for j := i; j < len(s); j++ {
+            if s[i] == s[j]{
+                if j-i <= 1{ // 情况一和情况二
+                    length = j-i
+                    dp[i][j]=true
+                }else if dp[i+1][j-1]{ // 情况三
+                    length = j-i
+                    dp[i][j] = true
+                }
+            }
+        }
+        if length > maxLen {
+            maxLen = length
+            left = i
+        }
+    }
+    return s[left: left+maxLen+1]
+}
+
 
 ```
 

problems/0100.相同的树.md

@@ -237,6 +237,26 @@ class Solution:
         return True
 ```
 Go：
+> 递归法
+```go
+func isSameTree(p *TreeNode, q *TreeNode) bool {
+    if p != nil && q == nil {
+        return false
+    }
+    if p == nil && q != nil {
+        return false
+    }
+    if p == nil && q == nil {
+        return true
+    }
+    if p.Val != q.Val {
+        return false
+    }
+    Left := isSameTree(p.Left, q.Left)
+    Right := isSameTree(p.Right, q.Right)
+    return Left && Right
+}
+```
 
 JavaScript：
 

problems/0129.求根到叶子节点数字之和.md

@@ -250,20 +250,20 @@ Go：
 
 ```go
 func sumNumbers(root *TreeNode) int {
-	sum = 0
+    sum := 0
-	travel(root, root.Val)
+    dfs(root, root.Val, &sum)
     return sum
 }
 
-func travel(root *TreeNode, tmpSum int) {
+func dfs(root *TreeNode, tmpSum int, sum *int) {
     if root.Left == nil && root.Right == nil {
-		sum += tmpSum
+        *sum += tmpSum
     } else {
         if root.Left != nil {
-			travel(root.Left, tmpSum*10+root.Left.Val)
+            dfs(root.Left, tmpSum*10 + root.Left.Val, sum)
         }
         if root.Right != nil {
-			travel(root.Right, tmpSum*10+root.Right.Val)
+            dfs(root.Right, tmpSum*10 + root.Right.Val, sum)
         }
     }
 }